As of January 1, 2006, the FDA mandated that all nutrition labels include the number of grams of trans fat in a food item. Since then, it seems as though trans fats are always making headlines. KFC was sued for using oils with trans fat, the New York City Board of Health voted this past fall to prohibit the use of artificial trans fat in the City's 20,000 restaurants, and many products are now advertising that they are trans fat-free. So what is all the hype about?

Research RoundupTrans Fats and Fertility

In a recent study published in the American Journal of Clinical Nutrition in January of 2007, researchers at the Harvard School of Public Health found that the more trans fats a woman consumes, the more likely she is to be infertile.

The researchers conducted a study of 18,555 married, premenopausal women with no history of infertility who either attempted a pregnancy or became pregnant between 1991 and 1999. The diet of the participants was assessed twice during the follow-up period through use of a food-frequency questionnaire. For each 2% increase in the intake of energy from trans fats as opposed to carbohydrates, researchers found there was a 73% greater risk of infertility. The risk rose to 79% for every 2% of energy consumed as trans fats if they replaced omega-6 polyunsaturated fats. And for every 2% of calories from trans fats consumed in place of monounsaturated fats, the risk of infertility more than doubled. For a woman eating an 1800 calorie diet, 2% of energy consumed as trans fats is only 4 grams, which is not that much.

To try to totally cut out trans fats, avoid any product that lists hydrogenated or partially hydrogenated oils in the ingredient list.

What are Trans Fatty Acids?

Trans fats, short for transaturated fats, are artificial fats that are created through a process called hydrogenation. In this process, hydrogen gas is added to unsaturated fatty acids and liquid fats are converted to solid fats. The main purpose of this is to increase the shelf life and flavor stability of foods. Trans fats also add texture and density to foods, help to create spreadable products (i.e. margarine), and lower the cost of products.

Where are Trans Fats Found?

Trans fats are found naturally in animal foods in very small amounts. These natural trans fats, however, are not the focus in the media. Rather it is the artificial or man-made trans fats. These artificial trans fats are found in products containing "hydrogenated" or "partially hydrogenated oil". They are abundant in processed foods including margarines, shortenings, cakes, cookies, crackers, snack foods, non-dairy creamers, donuts, and more. Trans fats can also be found in deep-fried foods, such as fast foods.

Why are Trans Fats Bad for Us?

Originally, saturated fats, found in butter, cheese, and beef were thought to be the worst type of fat. Saturated fats increase total cholesterol by increasing both LDL ("the bad") and HDL ("the good") cholesterol. As a result, items like margarine (which contain trans fat) were thought to be good replacements for their saturated fat counterparts. Over time, however, it was discovered that trans fats actually have a worse effect on cardiovascular disease risk. Whereas saturated fats raise both bad and good cholesterol, trans fats actually raise bad cholesterol and lower good cholesterol, causing the arteries to become clogged and increasing the risk of developing heart disease and stroke. Trans fats may also increase cardiovascular disease risk by triggering inflammation. In addition, trans fats may have a possible connection to insulin resistance and may increase risk of diabetes.

How can we Avoid Trans Fats in the Diet?

Identify high fat and trans fat foods. Start to read food labels and review the ingredients listed. Avoid foods with "hydrogenated" or "partially hydrogenated" oils. This is especially important if the hydrogenated oil is listed as one of the first ingredients. This means there is a lot of it in the food product. Sometimes you may see that a products is listed as containing zero trans fat grams but still has partially hydrogenated oil in the ingredient list. This is because a food product can claim to have zero grams of trans fat if it contains less than 0.5 grams.

Non-dairy creamer and international and instant latte coffee beverages

Margarine, shortening

Choose alternative fats. Try olive, canola, peanut, or flax oils in place of the hydrogenated stuff.

Eat Fresh. Aim for more fresh fruits and vegetables. Try new recipes with fruits, veggies, beans, or chicken. If you make the food, you will be able to opt for the healthier fat options.

How Much Trans Fat is Too Much?

There is no set numerical value of trans fat that is regarded as "too much".

However, the American Heart Association recommends that trans fats in the diet should be restricted to less than 1% of the energy consumed by the body. This usually translates into less than 2 to 3 grams per day. Currently, the FDA estimates that the US population consumes about 5.8 grams of trans fat or 2.6% of calories as trans fats. For the good of our bodies, let's start to bring that number down.

But beware of products that advertise themselves as "trans-fat free", that doesn't mean they are fat-free. In fact, many items still contain a fair amount of saturated fat. So keep reading those labels!

Provided by Heather Bauer, a Registered Dietician (RD) specializing in the interrelation between eating habits, metabolism, and lifestyle. Visit nu-train for more tips and tricks and sign up for her monthly newsletter.

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